Carbureter.



H E. CURTIS.

CARBUHETER.

APPHCATION FILED FEB."?. 1916 Patented Oct. 23, 191

FI URE 2 10 particularly to the means for; 1'

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pe f s e r nt Patented Oct. Q3, 1917.

Application lll'ed'lehruary, 7, 1918. Serial No. 76,781

To whom/may concern: I 'known th t I, HENRY E. CURTIS,

B, i a citizen of the United States, and resident of San *Jose, in the county otstnta Clarsr andfitate of California, have invented certain -I'iew' and useful Improvements in Carburetersy of which the following is a specification. r Y

My invention relates to carbpregers and gulating the tueliand air mixture in thelsame, reference bein :mad 0 my co-pentling application' Seria No. ,363, filed May '27. 1916. Theprincipal object of my invention is to provide meaii's for automatically regulating the inflow of air into the mixing chamber. of the carbureter so that the quanof 'air drawn will at all times be v proper proportion to the ganlount'of fuel ti on being used, and to provide a' mean's of the naturespecified that will bejsimplm; compact, efiicient, aiid cheap to manufacture.

With the above and othg objects in view,

the invention consists in e novel and use ful formation, construction, combination and relative arrangement of partsas'hereinafter described,-and illustrated in the accompanying drawings, in which-' Figure-1 shows a sectional' view ofa'carbureter embodying my invention.

Fig. 2 shows a sectional view on line A-A of, Fig. '1. I

Similar c aracters of reference refer to similar parts throughout-the several news.

Referring now more particularly to the drawings, 1 indicates the float chamber of a carburetor, 2 the inner wall of said chamber, 3 the float, and 4 the liquidfuelin said At 5 is indicated the mixing chamber.

hichamber provided with a throttle valve 6.

liriixinp; chamber 5 is shown cylindrical in shape and is'a 'continuatlon of primary air iohamber'i, said air chamber 7 being formed of the' inner wall 2 of float chamber 3." A

, shoulder 8 is formed in the inner' surface of wall. 2 as shown and for the purpose hereinafter set forth; At 9 is'shown a spraying. tube concentrically and axially positioned in said primary air chamber 7, the same being held in position by webs 10 preferably cast as an integral part of inner wall 2. Chamher 11 with its outer end closed by plug 12 and connected to float vchamber 1 by con-n form to slide easilyin charn'er 7i duits 18, provides a means by which fuel may be drawn from float chamber '1 through spraying-tube 9 to the carbureti'ng chamber f the carbureter. At 14 are shownair inlot orts to the mixing chamber 5. At 15; I show a true Venturi tube slid ably positioned in primary air chamber 7 in the following manner and having the following characteristics. :The lowermost portion of the tube has an inner surface 16 in the form 'of a short truncated cone joined to the lower and smaller end of a eo rnpara tively longer truncated cone 17 by a short throat-piece 18. Theoutersurface of the lower portion of said Venturi tube 15 is of such a form and size as to slide easily in the lower portion "of secondary air chamber 7, and is provided with. a flange '20 of the proper size in wall 2. The outer surface or the upper portion of tube 15 is ofthe. roper' size and A large proportion of theeiiteriorofithe wall of cone 17 is cut away to form an passage 21 and-to reduce the weight of said Yenturi tube 15. A plurality o'f-orifiees are own at 22 so posit/ioned in tube 15 as to permit the passage or air through openings 14 to mixing cha her 5 when tube 15 is advanced a distance. -At 23 are shown a plurality of ungularly positioned orifices in tube,15 connecting miking chamber 5 with air passage 21.

When this carbureter is in position and in full operation its action is as follows:-

Assuming that tbeen'gine is running under a light load, a comparatively small amount of .fnel is being used and the proper amount of air, is being drawn in through air chamber 7 and throat-piece 18 because Ven turi tube 15 is in a retracted position and the discharge end 24. of spray-infi'tube 9. is thereby advanced into cone ll'and-no air is beingdrawn through ports '14 I new the engine load isnncreased and the throttle valve 6 opencd'wide and an in creased amount of air and liquid fuel is air through orifices 22 and 2 causes Vcn" turl tube 15 to adi'ance to a pos1t1on,'say,as-

course, to the contracted space re the cones -16 and 17;

indicated in dotted lines at 25, the discharge and 24 of spraying tube. 9 bemgnow positioned in approximatelythe center of throat-piece 18. Orifices 22 now permit air to be drawn in throu h increased velocity tliroat piece 18 raws an increased amount of liquid fuel from the discharge end-of s raylng tube' 9, the increased velocity of t e air In said throat-piece 18' being due, of ative to It'may I improved carburetor is entlre'ly automatic,

as the positionofVenturi tube depends I: entirely upon the pressure within the mix- '15-is' ad '20 I cushion is shoulder 8 and I thereby qbtain'the eflec't ofa .dash-pot, and this i for theaexa shown and described is the. most desirable.

1s understood that the.

mg chamber 5, When the engine load is heavy and the fluid .rcssure light the tube aueed as own, a large amount f a r is drawn into mixing chamber 5 and a proportionallvlarge 'amountof liquid fuel is drawn from float chamber-1. As the engine load lightens the diminished suction of air permits tube 15 to recede thus diminishing the suction of liquid fuel from spraying tube 9.:

Byfittingventurl tube 15 fitting snuglyagains'tiwall 2 and the outer surface of. the lowermost portion of Venturi 15f-a1so fitting snugly against wall 2 an air provided between flange 20 and 1s desirable 1a provides for necessities of. :engme, and thus provides 7 proportioning of the liquid viuefand air mixture during any and all p itions of the. throttle valve. Tube-15 should beniade preferably cast aluminum, and thereforejis exceedingly sensitive to changes in engine I loads and speeds unda stea of-thesame.

necessary to prevent ch'atteri 'g or flutte'rin' in the. manner above describe used to; indicate that tube ,15, fits fclosel" 20 and I lower portion of. thetube; and wall BJto indicatethatia.tighfifit'is not desired and that irear-fp'ass therethron h. Of cm'irsent esefi u used, depends upon the-.jvyei'ghfiofi tebelb l .maf

herein shownand"'*lde scmbed one raw-tenor of said tu' While I have herein-described and sliown openings 14, and the air passing through.

I provided with an air now beseen that the action of my.

into position as hereinbefore described,"- with flan 20' I ik thereof and. a' a gradual mov m g'll fi emuri: tub -15 in either direptiowiccording to the ofu suitable light material, I

yingjmeuns is The air cushion 'rovided for I provides ape'rfect steadying means-fori the tube, the

' term snugl y .in' wall 2, aspace eing shfm'vh-in the draw in'g between flangethereof-and ii I tiolled Ventum tube tall 2 and the one particular .fO Ym of construction of my improved carburetor, it is understood that chan es in form and "construction and minor 'detai s'may be made within the scope of the appended claims, 7 7g Havin thus described my invention, what I cfiiini as new and desire to secure by .Letters Patent, is, I 1, Thecombination. of a carbureter body and a fiuid-pressure-controlled Venturi tube slidably mounted therein, 'said tube being assage on the exterior thereofnand a pluraiit of upwardly and inwardly directed pe orations connectin said .air assage withthe interior of sais tube; an means forsteadying the mov ments of said tube. 2. The combination of a carbureter body provided with compensating air inlet orts,= d a fiuid-pressureeontrolled Venturl tubei ably mounted therein, said tube havin 1 a passa e formed in the exterior thereo a plurality of, erforations formed therein 'connectin sai passage with the interior I of said tu and'a' plurality of perforations} formed therein connecting the exterior of@ said tube above Said passage with-the" in- 'f' terior-thereof, said passage and; said lasti mentioned perforations being adapted to}. communicate with said inlet ports .when said i tube is 'advanced .J j fgi'Thez ombgigaimrbfra o'fibureter bodf; lig ingsaehofi" er formed in the inner we I;

perforated fluid-pressure-con-g trolledive'nturl tube slidably mounted therein and provided with an airjpassae on the? exterior thereof and a flange a apted toi coiiperate with snidfshoulder and thereby?- pgovrde a dash-pot action for said tube, said i perforations being angularly positioned -ivith relation-to a diametrical plane passing 4 through said tube and connecting said 'pas- 'sug'e with the interior of said'tube, and a. plurality of inlet ports in theupper-portiofi'f. of su' j d''curburete'r"body adapted to com- '11!) 1s advanced. l '4'. The combination of aparbureter body; havin'g;a.sheulideriormedin the. inner-wall rfora'ted fluid-pressure-con slidablymounted there- 'in and -providedwith an air; passageon the; 7

exterior thereof and a flange adapted to'co operate with said shoulder. and therebyprovlde a dashot action forsaidtube, said perforations sing angularlyypositioned with relation to a diametrical i plane assing through said tube, a plurality of Sci perfo .ratiou lconn' 'said-passagqwith the in-- ody adapted tocommunicate with said 180 I and a'plurality of said perforations con'ne'ctin'g'the' outer-surface of. I

last mentioned perforations and said passage when said tube is advanced.

5. The combination of a carbureter body provided with compensating air inlet ports, and a perforated fluid-pressure-controlled Venturi tube slidably mounted therein, said tube being provided with a plurality of up wardly and inwardly directed perforations and having a range of movement that places said perforations in communication with said inlet ports when said tube is advanced and closes said ports when said tube is retracted. r

6. In a carbureter, the combination of a carbureter bo provided with inlet ports in the uppernortion thereof and having a shoulder formed in the inner wall thereof,

a float chamber, a mixing chamber and a spraying tube, means for permitting the passage of liquid from said float chamber to said mixingchamber through said spraying tube, and a perforated fluid-pressurecontrolled Venturi tube rovided withacarbureting chamber slidab y mounted in said carbureter body and axially positioned with relation to said spraying tube and with a range of movement that places said perfo rations in communication with said inlet ports and the discharge end of said spraying tube in the throat portion of said Venturi tube when said tube is advanc d and closes said inlet ports and places is discharge end of said spraying tube in said "carbureting-chamber when said Venturi tube is re tracted, thereby automatically PIOPOIUOD."

' ing the flow of fuel to the flow of air, said Venturi tube havin an annular flange formed thereon adapted to enga e shoulder and thereby provide; a ash-pot action for said tube.

'7. The combination ofla carbureter body provided with compensatin air inlet ports,

and a fluid-pressure-control ed Venturitube slidably mounted therein, said tube having an air passage formed on the exterior thereof and a p uralityof upwardly and in,- wardly directed erforations formed therein connecting sjai passage with the interior of saidtnbe, said passage being adapted to provided with compensatin communicate with said inlet ports when said tube is advanced. I

8. The combination of a carbureter body provided with compensating air inlet ports, and a perforated 'fluid-pressure-controlled Venturi tube slid-ably mounted therein, said tube being )rovided with a pluralit of upwardly and inwardly directed per orations and having a range of movement that places said perforations in communication with said inlet ports when said tube is advanced and closes said ports when said tube is retracted, and means for steadying the movements of said tube.

9. The combination of a carbureter bod'y connectin said passage with the interior of said tu e, and a plurality of pertorat' m formed therein connecting the exterior JJI said tube above said passage with the interior thereof, said passage and said last mentioned perforations being adapted to communicate with said inlet ports whensaid tube is advanced, and means for steadying the movements of said tube,

10. The combination of a carbureter bod-y provided with compensating air inlet ports, :30

and a fluidpressure-controlled Ventun tube slidably mounted therein, said tube having a passa'geformed on the exterior thereof, a plurality of upwardly and inwardly directed perforations connecting said passageijfi with the interior of said tube, and a p1u-' rahty of; upwardly and inwardly directed perforations formed therein connecting the exterior of said tube above saidpassage with and said last mentioned perforations'bemg adapted to communicate with said 'inlet ports When' the interior thereof, passa saidtube is advanced, and meansforsteady-.

the 'movementiofsaid tube. 4

la testimony 'whereof-I have hereunto 9'5 afiixed mysignature'thisQnd day of Febru- V ary, 1916. P a

HENRYCURTIS.

air inlet ports, 65' 

